Prevalence of zygomatic air cell defects in a North American population.

Zygomatic air cell defects (ZACDs) are asymptomatic defects present in the zygomatic process and articular eminence of the temporal bone. This defect is considered a normal anatomical variant and can be detected on routine panoramic images. The objective of this study was to determine the prevalence, dominant type, and location of ZACDs in a North American population. A total of 1724 panoramic images of adult patients were analyzed by a third-year dental student in conjunction with an oral and maxillofacial radiologist. Patient demographics (age and sex) as well as ZACD location (unilateral right/left or bilateral) and appearance (unilocular or multilocular) were evaluated. Statistical analyses included the Clopper-Pearson method to calculate the 95% CI, Student t test for independent samples, and Fisher exact test. The prevalence of ZACDs in this study population was 2.1%. A total of 24 women (2.3%) and 12 men (1.7%) were affected, with no statistically significant difference between the sexes. The mean (SD) age of patients presenting with a ZACD was 56.6 (17.7) years, while that of patients without a ZACD was 53.0 (16.3) years, with no statistically significant difference between groups. Among the 36 patients with ZACDs, 28 (1.6%) had unilateral and 8 (0.5%) had bilateral lesions. One patient with bilateral ZACDs had a unilocular lesion on the right side and a multilocular lesion on the left, so there were a total of 31 unilocular lesions (1.8%) and 6 multilocular lesions (0.3%). The results of this study indicate that the prevalence of ZACDs in the study population was 2.1%, without any statistically significant differences based on the sex or age of the patient or laterality or appearance of the lesions.

Utilization of p53 and p16 Immunohistochemistry in the Classification of Human Papillomavirus-Associated, p53 Wild-Type, and p53 Abnormal Oral Epithelial Dysplasia.

p53 immunohistochemistry (IHC) has recently been shown to be a clinically useful marker for predicting risk of progression to invasive squamous cell carcinoma in oral epithelial dysplasia (OED). The literature supports the use of p53 IHC as a marker to identify TP53 mutation in in situ and invasive vulvar lesions and as a surrogate marker for high-risk human papillomavirus (HPV) infection, but there is little documentation for similar use in OED. The purpose of this study was to determine whether p53 IHC is a reliable surrogate marker for detecting both TP53 mutation and high-risk HPV infection in OED. We studied 57 cases of OED (11 mild, 18 moderate, and 28 severe), and all were stained for p16 and p53 IHC. High-risk HPV RNA in situ hybridization (ISH) was performed in selected cases (all p16-positive cases and all OED showing abundant apoptotic cells and karyorrhectic cells; N = 27). Targeted next-generation sequencing (NGS) was performed in 33 p16-negative cases and all high-risk HPV RNA ISH-negative cases (N = 36). We identified 21 cases with p53 basal sparing patterns (mid-epithelial and markedly reduced [null-like]), 14 cases with p53 wild-type patterns (scattered basal and patchy basal/parabasal), and 22 cases with p53 abnormal patterns (18 overexpression, 3 null, and 1 novel cytoplasmic pattern). Among cases with p53 basal sparing patterns, 20 were positive for p16 (20/21, 95%), and all were positive for high-risk HPV RNA ISH (21/21, 100%). The 36 sequenced cases had IHC patterns concordant with TP53 mutation status in 92% (33/36) of lesions. This study demonstrates that p53 IHC expression patterns are sensitive and specific for detection of both high-risk HPV infection and TP53 mutation. Coupled with selective p16 IHC testing, this IHC panel can accurately subclassify OED into HPV-associated, p53 wild-type (conventional), and p53 abnormal OED.

Abnormal p53 Immunohistochemical Patterns Shed Light on the Aggressiveness of Oral Epithelial Dysplasia.

The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of mild, moderate, and severe dysplasia is considered by many the gold standard in predicting the risk of malignant transformation. Unfortunately, some low-grade lesions, with or without dysplasia, progress to squamous cell carcinoma (SCC) in short periods. As a result, we are proposing a new approach to characterize oral dysplastic lesions that will help identify lesions at high risk for malignant transformation. We included a total of 203 cases of oral epithelial dysplasia, proliferative verrucous leukoplakia, lichenoid, and commonly observed mucosal reactive lesions to evaluate their p53 immunohistochemical (IHC) staining patterns. We identified 4 wild-type patterns, including scattered basal, patchy basal/parabasal, null-like/basal sparing, mid-epithelial/basal sparing, and 3 abnormal p53 patterns, including overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, and null. All cases of lichenoid and reactive lesions exhibited scattered basal or patchy basal/parabasal patterns, whereas human papillomavirus-associated oral epithelial dysplasia demonstrated null-like/basal sparing or mid-epithelial/basal sparing patterns. Of the oral epithelial dysplasia cases, 42.5% (51/120) demonstrated an abnormal p53 IHC pattern. p53 abnormal oral epithelial dysplasia was significantly more likely to progress to invasive SCC when compared to p53 wild-type oral epithelial dysplasia (21.6% vs 0%, P < .0001). Furthermore, p53 abnormal oral epithelial dysplasia was more likely to have dyskeratosis and/or acantholysis (98.0% vs 43.5%, P < .0001). We propose the term p53 abnormal oral epithelial dysplasia to highlight the importance of utilizing p53 IHC stain to recognize lesions that are at high risk of progression to invasive disease, irrespective of the histologic grade, and propose that these lesions should not be graded using the conventional grading system to avoid delayed management.

Investigating Dental Aptitude Test (DAT) results as predictors for preclinical and clinical scores in dental school.

OBJECTIVE: The aim of the present study is to determine whether 2 current admission criteria, the perceptual ability test (PAT) and the manual dexterity test (MDT) can predict success in dental school within the Université de Montréal population. METHODS: A retrospective cohort study was conducted using the records of 854 students who graduated between 2005 and 2015. For each student, PAT and MDT scores were compared to 5 preclinical and 3 clinical classes using the Pearson correlation coefficient and regression models. T-tests were used to compare students above and below a 5-point increase in cut-off scores (PAT = 15, MDT = 10). RESULTS: The strongest relationship was found to be between PAT and preclinical scores (r = 0.329, P < 0.01). The regression analysis determined that gender, PAT and MDT predicted more of the variability of preclinical (12.7%) than of clinical scores (2.7%). Students scoring ≥10 on the MDT performed better in preclinical and clinical courses, and those scoring ≥15 on the PAT performed better in preclinical courses. However, when comparing these students to the entire group, only those scoring ≥15 on PAT differed from the group's average for preclinical scores (P = 0.029). CONCLUSION: These findings suggest the PAT and MDT have some power in predicting success in preclinical, and to a lesser extent clinical courses, and supports their use as criteria in the admissions process. There is some evidence that suggests that increasing the cut-off score may decrease the number of students with difficulties in preclinical courses.

Novel assessment of haemodynamic kinetics with acute exercise in a rat model of pulmonary arterial hypertension.

NEW FINDINGS: What is the central question of this study? The acute effect of exercise at moderately high intensity on already-elevated pulmonary arterial pressures and right ventricular wall stress in a rat model of pulmonary arterial hypertension (PAH) is unknown. What is the main finding and its importance? We show, for the first time, that in a rat model of PAH, exercise induces an acute reduction in pulmonary artery pressure associated with lung endothelial nitric oxide synthase activation, without evidence of acute right ventricular inflammation or myocyte apoptosis. Haemodynamic measures obtained with traditional invasive methodology as well as novel implantable telemetry reveal an exercise-induced 'window' of pulmonary hypertension alleviation, supporting future investigations of individualized exercise as therapy in PAH. Exercise improves outcomes of multiple chronic conditions, but controversial results, including increased pulmonary artery (PA) pressure, have prevented its routine implementation in pulmonary arterial hypertension (PAH), an incurable disease that drastically reduces exercise tolerance. Individualized, optimized exercise prescription for PAH requires a better understanding of disease-specific exercise responses. We investigated the acute impact of exercise on already-elevated PA pressure and right ventricular (RV) wall stress and inflammation in a rat model of PAH (PAH group, n = 12) induced once by monocrotaline (50 mg kg(-1) , i.p.; 2 weeks), compared with healthy control animals (n = 8). Single bouts of exercise consisted of a 45 min treadmill run at 75% of individually determined aerobic capacity (V̇O2max). Immediately after exercise, measurements of RV systolic pressure and systemic pressure were made via jugular and carotid cannulation, and were followed by tissue collection. Monocrotaline induced moderate PAH, evidenced by RV hypertrophy, decreased V̇O2max, PA muscularization, and RV and skeletal muscle cytoplasmic glycolysis detected by increased expression of glucose transporter-1. Acute exercise normalized the monocrotaline-induced elevation in RV systolic pressure and augmented pulmonary endothelial nitric oxide synthase activation, without evidence of increased RV inflammation or apoptosis. Real-time recordings of pulmonary and systemic pressures during and after single bouts of exercise made using novel implantable telemetry in the same animal for up to 11 weeks after monocrotaline (40 mg kg(-1) ) corroborated the finding of acute PA pressure decreases with exercise in PAH. The PA pressure-lowering effects of individualized exercise associated with RV-neutral effects and increases in vasorelaxor signalling encourage further development of optimized exercise regimens as adjunctive PAH therapy.